CVE-2021-41551Network attack vector

Administrator file disclosure via symlinked ZIP upload

Published Jan 18, 2022 · Updated Aug 4, 2024

Directory traversal in Leostream Connection Broker 9.0.40.17 allows remote authenticated users to read files via a crafted ZIP upload. The Administrator Web interface extracts an uploaded ZIP archive into /home/leo/app/tpc without preventing embedded symbolic links from redirecting file access. Administrator privileges and network access to that interface are required, and successful exploitation exposes files reachable by the broker process.

CVSS severity4.9
Medium
EPSS probability1.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Directory traversal in Leostream Connection Broker 9.0.40.17 allows remote authenticated users to read files via a crafted ZIP upload. The Administrator Web interface extracts an uploaded ZIP archive into /home/leo/app/tpc without preventing embedded symbolic links from redirecting file access. Administrator privileges and network access to that interface are required, and successful exploitation exposes files reachable by the broker process.

The record

CVE
CVE-2021-41551
Published
Jan 18, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-59
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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